The founder of the van Loo dynasty of painters was the Dutchman, Jacob van Loo (1614-70), who was obliged to flee Amsterdam after killing someone in a pub brawl. Having settled in Paris his son, Louis Abraham, and grandsons, Jean-Baptiste (1684-1745 and author of several works in the Royal Collection) and Carle-Andre (1705-65), all made successful careers in France. Jean-Baptise had two painter sons, Louis-Michel (1707-71) and Charles-Amedee-Philippe (1719-95), the author of this portrait. Charles-Amedee-Philippe trained with his father and won the Prix de Rome in 1738. He spend two periods working at the court of Frederick the Great in Berlin, from 1748 to 1758 and from 1763 to 1769, the years during which this portrait must have been painted.

The King is shown as a man of action, wearing a breast plate over a simple military coat, with boots and breeches. His rank is conveyed by the throne embroidered with a crown following the design of the one made for his father, Frederick I. The same crown also appears on his crimson ermine-lined mantle, draped over the throne. He wears the orange sash and badge of the Royal Prussian Order of the Black Eagle. A laurel wreath of victory encircles the crown on his throne and some laurel grows through the balustrade in the background.